From May to October, the Sacramentoregion is subject to regular and frequent days marked by ground level ozone... the primary ingredient in smog. During this time of year, area air districts issue "Spare the Air" advisories when such days are forecast. Summers typically see about 25 Spare the Air advisories issued.

On Spare the Air days, residents are asked to be particularly aware of airborne pollutants they may be contributing to the environment and are asked to make a personal effort to reduce such pollutants. Suggestions for significantly reducing individual contributions include: